How To Paint Your Car - Gun Control

When it Comes Time to Paint Your Car, Proper Technique is Just as Important as Using the Right Materials

Quality materials help make for a kick-ass paintjob, but even $600-a-gallon paint looks worthless if applied incorrectly. Conversely, bargain-basement paint can yield excellent results if applied properly. As the old saying goes, "it's the craftsman, not the tool." Still, painting a car isn't rocket science so long as you adhere to a few rules and know a few tricks.

To get some pointers, we headed over to the Los Angeles Trade Technical College (LATTC) where Collision and Repair instructor Brian Ferre was finishing up on an '87 Camaro in the paint both. Brian is responsible for teaching the next generation of painters how to do it right, so we figured he could school a magazine editor on the basics of laying down paint the right way.

What we learned is that it's all about control: contaminant control, gun position control, and flow control of the paint. It sounds easy, but the process of shooting paint is a sort of Zen deal where a painter goes by feel more than by gauges when laying down paint to be sure it's neither too thick nor too thin. For beginners, Brian suggested buying some cheaper paint, finding an old hood or panel, and practicing until the process becomes second nature. To that end, here are a few tips he passed onto us.

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01. This HVLP (high volume, low pressure) gun is the industry standard due in part to environmental regulations, but mainly because it allows for better paint control and less wasted product. They generate far less overspray compared to high-pressure siphon-fed guns, but on the flip side they are more expensive. The old siphon-fed type can be identified by the paint feed can attached on the bottom. The type of gun is less important than it being clean and in good working order. Also mandatory is that the gun have a regulator/air-adjuster controller, even if there's a pressure regulator on the compressor. This is because each type of paint requires a different amount of air pressure, and even things like the length of the air hose can affect the air pressure from the compressor. The "high volume” part of the HVLP gun means you need a stout compressor to keep up with demand.

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02. Our third-gen was shot in Axalta Cromax Pro two-stage paint, and in this article we will be shooting the hood vents in a low-gloss black from their Hot Hues line. We also used their A-3990S Surface Klean to make sure the surface was free from any oils or other contaminants.

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03. Brian Ferre even schooled us on the right way to stir paint. Stirring in a circular motion just moves the components around. The better method is to move the stick in a "left to right” motion since it better mixes the components.

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04. Brian also told us to take care when installing the cap on the paint cup since the liner can fold over and cause a big mess when the assembly is inverted.

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05. HVLP guns are designed, as the name implies, to shoot at low pressures, typically in the 3 to 5 psi range. Nonetheless, most painters shoot at a slightly higher pressure of up to 10 psi. Still, every primer, basecoat, and clear will have its own sweet spot in terms of pressure. With this in mind, it's always a good idea to do "spray outs” on some unused paper to get the flow dialed in. Getting the right flow is a balancing act between the fan (spray) size and the air flow. In case you're curious, the older, siphon-type guns operate at pressures from about 30 to 50 psi.

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06. Here's the section of our Camaro's hood that will be shot in Hot Rod Black. The HVLP guns generate less overspray, but you'll still want to make sure the rest of the car is covered up.

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07. Prior to painting, the area needs to be wiped down. For this, Brian used the aforementioned Surface Klean and some DuPont Sontara Solvent Wash and Dry Cloths (PN E-4142). The blue cloths are lint-free and designed to work with solvents and not contaminate the work area. Again, compressed air is used to blow any lint or dust away from the area to be painted.

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08. Brian also likes to feel the surface with his bare hand before painting. This way he can find any imperfections that might go unnoticed if he were wearing a glove. Of course, it's important to make sure your hands are clean before doing this. He also uses air during this process to blow away any bits of dust knocked loose by his hand.

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09. Before spraying, the entire front of the car, including the paper, was gone over with a tack cloth. This helps remove any dust or dirt that might blow around while spraying and contaminate the paint.

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10. When you're laying down paint, make sure to go well past the edge of the paper. This ensures that the area receives the same amount of paint at the edges as it does in the center. This is one time where it's a good idea to paint outside of the lines. Brian suggests maintaining an overlap of 50 percent for solvent-based paints and 75 percent for water-based paints.

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11. While spraying, the keywords are "parallel” and "perpendicular.” That's to say you want to avoid swinging the gun in an arc and make sure it stays the same distance (the parallel part) from the car's surface during the entire pass. If you move the gun in an arc, you'll end up with more paint in the middle and less at the edges where the gun is farther away, which is not what you want. Remember, consistency is king.

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12. Perpendicular to the car just means that you want the gun to be pointed at the car and not shooting the paint at an angle to the surface. Since we're shooting a small area, Brian used a SATA Minijet gun. Because it's putting out a smaller pattern, it's held about 4 to 6 inches from the car. With a larger gun (for shooting the main body color) the proper distance would be around 7 to 10 inches.

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13. The goal is to lay down two wet-looking coats with the second coat being a bit heavier than the first. Remember that consistent gun movements will result in an even coat of paint. Also, don't stop spraying until the gun is well over the paper.

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14. Looking at the tape and paper can tell you if you're doing it correctly. The lack of paint on this tape edge tells us that we most likely didn't get enough paint where we wanted it. Trust us that any dry spots will really show up later, so make sure the edges have as much paint as the center.

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15. This was a single-stage color, but the process for shooting clear would be the same. With clear, it's even more critical to follow the parallel and perpendicular rule as well as making sure to not stop short on the edges since dry spots in your clear will not give you the best possible results.